A cloud computing service virtualizes, on the basis of a service contract with a cloud user of the cloud computing service, a hardware group including a plurality of servers in a server facility and provides the cloud user with infrastructures itself such as virtual machines and networks of the hardware group as a service provided through a network.
As types of charging of the cloud computing service, in general, there are monthly charging and meter rate charging. The monthly charging is a contract form for billing a fixed monthly rate to the cloud user. The cloud user is charged with a fixed rate irrespective of whether the cloud user operated the virtual machine. For example, when the cloud user provides a Web service with the virtual machine in the server facility, since it is unknown when the virtual machine is accessed, the cloud user needs to always keep a server of the virtual machine in a started state. Therefore, the cloud user selects the monthly charging.
On the other hand, in the meter rate charging, the cloud user is charged with a rate according to time during which the cloud user operates the virtual machine. The cloud user operates the server of the virtual machine when the server is necessary, for example, when the cloud user operates the virtual machine only to perform monthly processing in the month end, and the cloud user stop the server when the server is unnecessary. In this case, the cloud user selects the meter rate charging.
The cloud computing service is described in Japanese Patent Application Laid-open No. 2010-224914.